Various systems use transponders to identify objects from a distance by associating a transponder with the object. Objects may be identified using, for example, either an active transponder or a passive transponder. An active transponder contains its own power source, whereas a passive transponder lacks its own power source. A passive transponder may, for example, obtain power from an electric or magnetic field provided by a reader. One class of transponders includes radio frequency identification (RFID) tags. For example, an RFID tag is programmed with a unique identification code that is used to identify a specific object the tag is attached to, and an RFID tag reader is used to retrieve the code from the tag. Electronic Product Codes (EPC) are also becoming popular, and may include a product class identifier as well as a unique identification code. These EPC codes may be stored in an RFID tag. Other types of systems may use a product class identifier, such as a Uniform Product Code (“UPC”) symbol, and a reader, such as a bar code reader, for reading the UPC symbol.
These systems differ in that they use different mediums for storing information about an associated object. For example, an RFID tag may store a code in memory and a UPC symbol may be provided on a printed medium. These systems are similar in that the information stored in the medium may be used to retrieve additional information about the object. For example, a UPC symbol may be scanned and information about the object is retrieved based on the scanned UPC symbol. However, a user interested in obtaining information about the object may have little or no control over the information retrieved. For example, scanning a UPC symbol may only result in retrieving static information about the object, such as all the information about the object stored in the reader system or a connected database.
Static information obtained from conventional transponder systems is of limited use and application. In addition, if the retrieved information is being transmitted over a network, having no control over the data being retrieved may result in long latencies or increased costs if a fee is associated with using the network.